The present disclosure provides a process for enhancing procatalyst and catalyst properties. The present disclosure provides formant polymers produced by these procatalysts/catalysts.
Worldwide demand for olefin-based polymers continues to grow as applications for these polymers become more diverse and more sophisticated. Known are Ziegler-Natta catalyst compositions for the production of olefin-based polymers and propylene-based polymers in particular. Ziegler-Natta catalyst compositions typically include a procatalyst containing a transition metal halide (i.e., titanium, chromium, vanadium), a cocatalyst such as an organoaluminum compound, and optionally an external electron donor. Many conventional Ziegler-Natta catalyst compositions include a magnesium chloride-supported titanium chloride procatalyst with a phthalate-based internal electron donor.
The health concerns from phthalate exposure are driving the art to find phthalate substitutes. Known are catalyst compositions containing an alkoxyalkyl ester (AE) as an internal electron donor for the production of propylene-based polymers. However, conventional AE-containing catalysts are currently not viable because their catalyst activity and/or selectivity are too low for commercial application. Desirable would be Ziegler-Natta procatalyst compositions containing an alkoxyalkyl ester internal electron donor with sufficient catalyst activity/selectivity for the commercial (i.e., large-scale) production of olefin-based polymers.